US 5,095,536 AGranted

Direct conversion receiver with tri-phase architecture

AssigneeRockwell International Corporation

InventorRoger K. Loper

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Abstract

A direct conversion receiver having a tri-phase architecture including three separate baseband signal channels. RF communications signals which are being tuned by the receiver are split into three equal and in-phase components which are mixed with three equal but substantially out-of-phase injection signals on frequency with the communications signal. The resulting baseband component signals are independently filtered and amplified on the three signal channels. The baseband components are then directed to a signal processing unit which corrects the baseband components for gain or phase mismatch errors between the signal channels based on the information carried by the three components and thereafter demodulates the signals in order to acquire the information carried by the RF communications signal. An automatic gain control system and a signal filtering system adapted for use with direct conversion receivers are also disclosed.

Claims34

Dependent claims

A direct conversion radio receiver, comprising:

RF coupler means for splitting an RF communications signal into first, second and third RF components provided on separate first, second and third signal channels;
synthesizer and splitter means for generating an injection signal.on-frequency of said RF communications signal and splitting the same into first, second and third injection signal components which are out-of-phase with each other by approximately 120.degree.;
first, second and third mixer means installed on said first, second and third signal channels for mixing said first, second and third RF components with said first, second and third injection signal components in order to produce first, second and third baseband signal components;
first, second and third low-pass filter means installed on said first, second and third signal channels for filtering said baseband signal components from said first, second and third mixer means in order to reject interference and spurious signals accompanying said baseband components;
first, second and third amplification means installed on said first, second and third signal channels for amplifying said baseband signal components;
and
signal processing means for processing the baseband components from said signal channels and using the information carried by these components to correct for gain or phase errors between the signal channels and demodulate these components so as to acquire the information carried by the RF communications signal.

4 more elements

Dependencies are inferred from the claim text.